TYPHLONECTES VENEZUELENSE and T

30 SHORT NOTES HERPETOLOGICAL JOURNAL,Vol. 6, pp. 30-31 (1996) Taylor's (1968) treatment of Typhlonectes intro duced radical changes. T. kaupii was transferred to a THE TAXONOMIC STATUS OF new genus, T. natans was resurrected to species status, TYPHLONECTES VENEZUELENSE and T. c. venezuelense was removed from the syn onymy of natans and elevated to specific status. In FUHRMANN (AMPHIBIA: T. addition, Taylor (1968) described three new species of GYMNOPHIONA: Typhlonectes. One of these new species, T. eiselti, is a TYPHLONECTIDAE) highly distinctive lungless caecilian that has been transferred to the genus Atretochoana (Nussbaum & MARK WILKINSON Wilkinson, 1995). Taylor's other new species cannot School of Biological Sciences, University of Bristol, be diagnosed on the basis of any features that reliably Bristol. BS8 1 UG. UK distinguish them from T. compressicaudus and are considered junior synonyms of that species At the tum of the last century, the genus Ty (Wilkinson, 1991 ). Nussbaum & Wilkinson (1989) phlonectes comprised three distinctive species, T. noted that T venezuelense was of doubtful validity and compressicaudus (Dumeril & Bibron), T. natans did not include this species in their synopsis of the con (Fischer) and T kaupii (Berthold) (= T dorsalis Pe tent of Typhlonectes. My aims here are to clarify the ters) from Northern South America, all of which taxonomic status of T venezuelense, describe simple showed some degree oflateral compression of the body distinguishing features for the speciesof Typhlonectes, and development of a dorsal 'fin' that set them apart and raise concerns over the taxonomic status of a re from all other caecilians and indicated adaptation to a cently described species. distinctive aquatic existence. In a classic early mono Taylor's (1968: 255) diagnosis of Typhlonectes graph on the aquatic caecilians, Fuhrmann (1914) venezuelense indicates that it has a distinctly higher described a new variety, Typhlonectes compressi (less flattened) head than does T natans, but includes caudus venezuelense, for a form represented by two no other features that might distinguish these forms specimens from Caracas and Maracaibo, Venezuela, [the diagnosis states "Head distinctly flatter than the distinguished from the Amazonian and Guyanan form head of natans." and "flatter" is corrected to "higher" T c. compressicaudus by minor and subtle differences in an Errata, that, unfortunately, is not included in all in head shape. Dunn (1942), who examined many copies of the work]. Neither Taylor nor I have been more specimens than were available to Furhmann, able to locate the holotype of T. venezuelense, a speci considered this form to be a junior synonym of T. na men catalogued in the Berlin Museum and which is tans, and he also considered natans to be no more than presumed lost, but I have examined available type ma a variety of compressicaudus. terial of both T venezuelense (ZMH A00257, TABLE I. Morphometric and meristic data forTy phlonectes natans and T. venezuelense. Typhlonectes venezuelense Typhlonectes natans ZMH A00257 ZMB 9523 LACM Paratype Cotype 67435 '67436 Total length 350 500 345 343 Circumference at mid-body 43 43 41 39 Primary annuli 92 93 88 90 Head length 10.7 12.7 10.8 10.7 Head width at eye 9.3 9.7 8.8 8.5 Head depth at eye 5.5 5.5 5.3 5.2 Head width at occiput 11.1 11.9 10.8 10.7 Head depth at occiput 7.3 6.5 7.0 6.7 Interorbital distance' 7.1 7.7 6.9 6.6 Internarial distance 4.6 4.4 4.6 4.5 Eye-narial distance 4.8 5.7 4.9 4.8 Eye-tentacle distance 4.3 4.9 4.5 4.4 Tentacle-narial distance 0.7 0.7 0.5 0.5 Premax-maxillary teeth 44 46 42 39 Vomeropalatine teeth 45 39 42 44 Dentary teeth 34 36 34 32 Splenial teeth 12 10 9 8 SHORT NOTES 31 The type specimens of Typhlonectes venezuelense are reported to be from Caracas and from Maracaibo, Venezuela. Other specimens of T. natans have been collected in the region of Maracaibo as recently as 1981 (Wilkinson, submitted). In contrast, no other t specimens of T. natans are known from Caracas, and whether the Caracas specimen originated in the vicin ity ofCaracas, or was collected elsewhere in the region, is uncertain. Cascon et al. ( 1991) recently described a new spe cies of Typhlonectes, T. cunhai from Manaus, Brazil, (a) (b) an area that has also yielded many specimens of T. FIG. 1. Diagrammatic representation of the patterns of compressicaudus. Unfortunately, the diagnosis of this denticulations surrounding the vent that can be used to new species, which, as in T. compressicaudus, has 10 distinguish those species of Typhlonectes with low numbers denticulations about the vent, emphasises features of of splenial teeth. (a) T. natans (b) T. compressicaudus. the body shape and fin that are notoriously variable in Arrow is directed posteriorly. T. compressicaudus, and provide no compelling evi dence that their new form is specifically distinct. The paratype) and T. natans (ZMB 9523 cotype) as well as uncertain status of cunhai represents the major unre several hundred specimens of T. natans. I can find no T. differences between the types that warrants their recog solved problem in the species level taxonomy of nition as distinct species. Diffe rences in the shape of Ty phlonectes. the head exist, but the relatively flat skull of the cotype Acknowledgements. I am grateful to Rainer Gtinther, Universitat Humboldt Zoologishes Museum (ZMB), H. of T. natans is attributable to the fact that the skull and cranial musculature are extensively macerated. Cer W. Koepke, H. Wilkens, and R. Dohse, Universitat tainly, other Typhlonectes from the vicinity of the type Hamburg Zoologische Museum (ZMH), and J. Wright, of T. natans in the Rio Magdellena-Rio Cauca drainage Los Angeles County Museum (LACM) for facilitating my studies of the important specimens in their care. I in Colombia, and which were readily assigned to T. natans by Taylor (1968, 1973), have less flattened thank Ron Nussbaum for his comments on the manu heads than does the cotype and do not differ in this re script. This work was supported in part by NERC grant GST/02/832 spect from the type material of T. venezuelense. Morphometric and meristic data for the type material, together with data for two specimens that were as REFERENCES signed by Taylor (1973) to T. natans, are summarised Cascon, P., Lima-Verde, J. S. & Marques, R. B. (1991). in Table 1. The latter specimens are from a single lo Uma nova especie de Typhlonectes da Amaz6nia cality, close to the type locality of T. natans, and they Basiliera (Amphibia: Gymnophiona: Typhlonectidae). are similar in total length to the paratype of T. Bot. Mus. Para. Emilio Goeldi ser. Zoo! 7, 95-100. venezuelense. As can be seen from Table 1, they agree Dunn, E. R. (1942). The American caecilians. Bull. Mus. closely with the paratype of T. venezuelense in their Comp. Zoo{. Harvard 91, 339-540. measures and counts, including those that reflectthe Fuhrmann, 0. (1914). Le genre Thyphlonectes [sic]. shape (width and depth) of the head. Fuhrmann Mem. Soc. Sci. Nat. Neuchatel 5, 112-138. (1914) described some minor differences in the dispo Nussbaum, R. A. & Wilkinson, M. (1989). On the sition of the lungs and urinary bladder of T. classification and phylogeny of caecilians (Amphibia: venezuelense and T. natans which are attributable to Gymnophiona), a critical review. Herpetol. Monogr. intraspecific variation. 3, 1-42. These observations support Dunn's (1942) earlier Nussbaum, R. A. & Wilkinson, M. (1995). A new genus conclusion that, in the absence of any significant dif of lungless tetrapod: a radically divergent caecilian ferences, Typhlonectes venezuelense must be (Amphibia: Gymnophiona). Proc. Royal Soc. B. 261, considered a junior synonym of T. natans. In contrast, 331-335. there are several major morphological differences be Taylor, E. H. ( 1968). The Caecilians of the World. tween T. natans and T. compressicaudus, (e.g. in the Lawrence: University of Kansas Press. dentition, relative lengths of left and right lungs and Taylor, E. H. ( 1973). A caecilian miscellany. Un iv. the form of the cloaca! disk [Taylor, 1968; Wilkinson, Kansas. Sci. Bull. 50, 187-23 1. 1991]) that do not support Dunn's view that these Wilkinson, M. ( 1991). Adult tooth crown morphology in formsare merely geographic races of the same species. the Typhlonectidae (Amphibia: Gymnophiona): a For the purposes of identification, T. natans and T. reinterpretation of variation and its significance. Z. compressicaudus can be distinguished most readily by zoo!. Sys t. Evolut.-fo rsch. 29, 304-311. the arrangements of the denticulations that radiate from the vent to form the cloaca! disk (Fig. 1). Accepted: 12. 5. 95 .

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